Genetic and evolutionary analysis of enterovirus 71 base dinucleotide.

In this paper, a comprehensive analysis of genome sequences of 99 EV71 virus isolates base dinucleotide odds ratio was conducted to explore the potential mechanisms of its evolution. The general correlation of dinucleotides at different sites of the codons reveals that mutational pressure is the main factor determining EV 71 evolution. Furthermore, the apparent geographic segmentation of isolates before 2008 and low-frequency appearance of TpA and CpG also suggest that the geographic and host factors play important roles in the evolution of the virus. Finally, obvious fluctuation and divergence of the dinucleotide usage pattern was observed in the EV71 isolated in China after 2008, which might reveal that the virus entered a rapid evolution period, especially after 2010. These results indicate that EV71 has more initiative and adaptability under external pressures.